1. Field of the Invention
The invention relates to a backlight unit and, in particular, to a light emitting diode (LED) backlight module.
2. Description of the Related Art
A liquid crystal display comprises a liquid crystal panel and a backlight unit. The liquid crystal panel comprises a thin layer of liquid crystal encased between upper and lower thin glass plates. An array of thin film transistors is disposed on the lower glass plate. The thin film transistors control liquid crystal passage of different brightness of emitted light. The backlight unit provides a light source.
FIG. 1 is a lateral view of a conventional LED backlight module. The light source is provided by light emitting diodes (LEDs). The LED backlight units LED1˜LED4 are set on the substrate 101. Light guide plate and other optical plates are set above the light source to improve luminescent efficiency. FIG. 2 is a top view of a conventional LED backlight module. The LED unit comprises red, green, and blue light emitting diodes. There is the same distance P between each LED unit. To maintain uniform brightness, the distance P between the LED units cannot be increased with brightness of the light emitting diodes. Thus, the amount of the light emitting diodes and cost cannot be decreased.